Experimental investigation of the thermosiphonic phenomenon in domestic solar water heaters

The deeper understanding of the ‘thermosiphonic phenomenon’ and the identification of the key parameters affecting it, is the main aim of a research project currently in process in Cyprus. In this work a review of the existing standards and scientific knowledge concerning domestic solar water heaters is presented. The first preliminary results of the experimental investigation of the ‘thermosiphonic phenomenon’ in domestic solar water heaters are also presented. For this purpose a special test rig was set up and equipped with all sensors necessary to measure all parameters that are most likely to affect the ‘thermosiphonic phenomenon’. All tests were conducted according to ISO 9459- 2:1995(E). At first, the solar collector was tested according to EN12975-2:2006 in order to determine the thermal performance characteristics at a flow and operation conditions specified by the standard. Consequently, the efficiency of the collector operating thermosiphonically was calculated based on quasi-dynamic approach. Finally, a series of correlations were attempted using the data acquired when the collector is operating themosiphonically which are the following: (i) the temperature difference of the water at the outlet and the inlet of the collector (ΔΤ) with the solar global radiation, (ii) the water mass flow with the solar global radiation, (iii) the water mass flow with the temperature difference of the water at the outlet and the inlet of the collector (ΔΤ). The results of the data analysis showed that these parameters are very well correlated between them since the coefficient of determination (R2) is over 0.91 in all cases

Investigation of the parameters affecting the thermosiphonic phenomenon in solar water heaters

Cyprus is currently the leading country in the world with respect to the application of solar water heaters for domestic applications, with more than 93% of the houses equipped with such a system. The great majority of these solar water heaters are of the thermosiphonic type. Thermosiphonic is a natural phenomenon where the flow of the solar heated water from the collector to the storage tank occurs from a small flow created due to the difference in density between hot and cold water. The main advantage of such systems is that they do not require a pump for circulating the water and circulation exists as long as there is sunshine. This reduces the maintenance requirements and the system is foolproof. In spite of the fact that extensive analyses of the performance of solar water heaters has been carried out by numerous researchers, almost all of them concerned forced circulation systems which use a circulating pump. Currently, the knowledge on the parameters affecting the ‘thermosiphonic phenomenon’ is rather poor while on an international level (ISO and CEN committees) there isn’t any standard to test thermosiphon solar collectors. The deeper understanding of the ‘thermosiphonic phenomenon’ and the identification of the key parameters affecting it, is the main aim of a research project currently in process in Cyprus. In this work the first preliminary results of the experimental procedure are presented. More specifically, a special test rig was set up and equipped with all sensors necessary to measure all parameters that are most likely to affect the ‘thermosiphonic phenomenon’. All tests were conducted according to ISO 9459- 2:1995(E). The system was able to operate in various weather and operating conditions and could accommodate the change of inclination of the collector. Initially, the solar collector was tested according to EN12975-2:2006 in order to determine the thermal performance at a flow and operation conditions specified by the standard. Subsequently, the efficiency of the collector operating thermosiphonically was calculated based on quasi-dynamic approach. Finally, a series of correlations were attempted using the data acquired when the collector is operating themosiphonically which are the following: (i) the temperature difference of the water at the outlet and the inlet of the collector (ΔΤ) with the solar global radiation, (ii) the water mass flow with the solar global radiation, (iii) the water mass flow with the temperature difference of the water at the outlet and the inlet of the collector (ΔΤ). The results of the data analysis showed that these parameters are very well correlated between them since the coefficient of determination (R2) is over 0.91 in all cases

Addressing the clinical unmet needs in primary Sjögren's Syndrome through the sharing, harmonization and federated analysis of 21 European cohorts

For many decades, the clinical unmet needs of primary Sjögren's Syndrome (pSS) have been left unresolved due to the rareness of the disease and the complexity of the underlying pathogenic mechanisms, including the pSS-associated lymphomagenesis process. Here, we present the HarmonicSS cloud-computing exemplar which offers beyond the state-of-the-art data analytics services to address the pSS clinical unmet needs, including the development of lymphoma classification models and the identification of biomarkers for lymphomagenesis. The users of the platform have been able to successfully interlink, curate, and harmonize 21 regional, national, and international European cohorts of 7,551 pSS patients with respect to the ethical and legal issues for data sharing. Federated AI algorithms were trained across the harmonized databases, with reduced execution time complexity, yielding robust lymphoma classification models with 85% accuracy, 81.25% sensitivity, 85.4% specificity along with 5 biomarkers for lymphoma development. To our knowledge, this is the first GDPR compliant platform that provides federated AI services to address the pSS clinical unmet needs. © 2022 The Author(s

Demonstrating usage diversity over an information-centric network

Information-Centric Networking (ICN) is becoming increasingly popular: various architectures have been proposed to transform today's host-centric networks to information-centric ones. An important question that begs to be answered is whether the ICN paradigm can adequately support various types of existing network usage, as well as set the foundations for new application types. In this demonstration, we exhibit four different communication models via corresponding applications supported by our architecture. All applications are realized through the publish/subscribe service model exported by our ICN nodes

Experimental Investigation of the Effect of Solar Collector’s Inclination Angle on the Generation of Thermosiphonic Flow

Cyprus is currently the leading country in the world with respect to the application of solar water heaters for domestic applications, with more than 93 % of the houses equipped with such a system. The great majority of these solar water heaters are of the thermosiphonic type. Currently, the knowledge about the parameters affecting the ‘thermosiphonic phenomenon’ is rather poor while on an international level (International Organization for Standardization, ISO, and Comité Européen de Normalisation CEN committees) there is no standard available to test thermosiphon solar collectors. The deeper understanding of the ‘thermosiphonic phenomenon’ and the identification of the key parameters affecting it is the main aim of a research project currently in process in Cyprus. In this chapter, the experimental results of the research project are presented. Specifically, a special test rig was set up and equipped with all the sensors necessary to measure all the parameters that are most likely to affect the ‘thermosiphonic phenomenon’. All tests were conducted according to ISO 9459-2:1995(E). The system was able to operate in various weather and operating conditions and could accommodate the change of inclination of the collector. During the experimental procedure, three different inclination angles of the solar collector were tested in order to evaluate their effect on the generation of thermosiphonic flow. The thermal performance of the collector was calculated both in thermosiphonic operation and also according to EN12975-2:2006 in order to determine the thermal performance at a flow and operation conditions specified by the standard. Finally, a series of correlations were attempted using the experimental results for the thermosiphonic operation of the collector which are the following: (i) the temperature difference of the water at the outlet and the inlet of the collector (ΔT) with solar global radiation, (ii) the water mass flow with the solar global radiation and (iii) the water mass flow with the temperature difference of the water at the outlet and the inlet of the collector. The results of the data analysis showed that the examined parameters were well correlated and also the optimum inclination angle in terms of the highest thermosiphonic flow generation was that of 45°

Physical Activity in Cardiac Rehabilitation: Towards Citizen-Centered Digital Evidence-Based Interventions

Physical activity is a vital part of cardiac rehabilitation (CR). However, heart-healthy physical activity levels in people with cardiovascular disease drop significantly after CR. This exploratory study employs qualitative and survey methods within a co-creation approach. The aim is to understand the mechanisms of healthy behavior and habit formation in order to create a novel evidence-based (post-)rehabilitation approach that employs digital means to sustain long-term physical activity levels in people with cardiovascular disease

Dementia-Related Barriers to mHealth Use: Validation by Expert Opinion

mHealth use for people with dementia is fraught with factors influencing its implementation in care and daily life. A better understanding of these factors may provide guidelines to inclusive design. This study aimed to assess whether factors gathered in a literature-based model could be validated by opinions of experts. On basis of a questionnaire as part of a larger study, experts identified barriers that they considered to be related to aging and dementia influencing mHealth use. Nineteen barriers that were mentioned by the dementia experts were covered in our literature-based model. No adaptions to the model were required. The dementia experts acclaimed three barriers to mHealth use that could not be mapped onto the framework: the unavailability of (informal) caregivers to support the mHealth use, the stage and type of dementia of an mHealth user, and the fear of the unknown. These should be considered as prerequisites in the implementation phase of mHealth and explored more in future research

SOIN-MI Data Lab: Personalized Ophthalmology Through Collaborative Data Collection and Dynamic Patient Consent

The Swiss Ophthalmic Image Network (SOIN) is part of the Swiss Personalized Health Network (SPHN). SOIN contains a collaborative, clinical research environment, MI Data Lab, which allows privacy-preserving, data-driven, research. Personalized care of chronic ocular disease, based on Machine Learning (ML) and medical imaging, can dramatically improve quality of life and reduce the burden on health and social care systems. MI Data Lab allows research partners to consolidate their data in a space where doctors and data scientists cooperate to design novel ML algorithms, on curated datasets. To date, we have created several algorithms to detect ocular biomarkers automatically, and applied such tools to 100k+ retinal images. MI Data Lab enables the development of predictive models, the extraction novel traits to be explored in terms of-omic associations, treatment outcome, and priors for disease progression

Evaluating mHealth Design for People with Dementia: Preliminary Results

The availability of mHealth for people with dementia is increasing. Various mHealth design guidelines for this population have been proposed. In this study, we developed a binary checklist with evaluation statements to assess the implementation of twenty design suggestions in seven currently available mHealth apps for people with dementia. Between 17%-65% of the evaluation statements in the checklist were implemented in these apps. Not all statements were considered applicable for each assessed mHealth app, which resulted in dividing the criteria in two groups as either key evaluation statements or optional evaluation statements. In future work we want to augment this checklist to contribute to the future design of mHealth for people with dementia

Pseudopodial and β-arrestin-interacting proteomes from migrating breast cancer cells upon PAR2 activation

Metastatic cancer cells form pseudopodia (PD) to facilitate their migration. The proteinase-activated receptor-2 (PAR-2) transduces migratory signals from proteases, and it forms protein complexes with β-arrestin and other signalling molecules that are enriched in pseudopodia. More generally, however, pseudopodial regulation is poorly understood. Here, we purified the pseudopodial proteomes of breast cancer cells after activation of the endogenous PAR-2 and we combined gel-based approaches with label-free high-resolution mass spectrometry to identify proteins that accumulate at the pseudopodia upon PAR-2-mediated migration. We identified > 410 proteins in the cell body and > 380 in the pseudopodia upon PAR2 activation, of which 93 were enriched in the pseudopodia. One of the pathways strongly enriched in the PD was the clathrin-mediated endocytosis signalling pathway, highlighting the importance of the scaffolding function of β-arrestin in PAR-2 signalling via its endocytosis. We therefore immunoprecipitated β-arrestins, and with mass spectrometry we identified 418 novel putative interactors. These data revealed novel β-arrestin functions that specifically control PAR-2-regulated signalling in migrating breast cancer cells but also showed that some β-arrestin functions are universal between GPCRs and cell types. In conclusion, this study reveals novel proteins and signalling pathways potentially important for migration of breast cancer cells. © 2013 Elsevier B.V